> For the complete documentation index, see [llms.txt](https://javascript-1.gitbook.io/javascript/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://javascript-1.gitbook.io/javascript/single-thread.md).

# Single Thread

* JavaScript is a single threaded programming language, that execute one process at a time.
* When the functions pushed into the call stack, the function in the stack will be executed ans poped out one by one.

#### Cons:

* Due to the single threaded, the process will be slow down.